Abstract

The central aim of this thesis was to expand on the current knowledge of factors which influence human tendon properties.
It is shown here that tendon elongation is 72% greater and calculated tendon stiffness 43% (p<0.05) lower when determined during a long duration contraction (10s) compared to a short contraction (3-4s). Therefore, in order to produce reliable measures contraction duration was
standardised (3-4s) throughout the work of this thesis.
Novel data for the mechanical properties of male and female patellar tendon were obtained in both young and elderly populations. In the young group both stiffness and Young's modulus were significantly lower in females compared to males (-39% and -19% respectively, p<0.05).
However, in the elderly there were no significant differences in tendon properties between genders. Elderly individuals possessed significantly lower levels of tendon stiffness and Young's modulus than their young counterparts with males showing 73% and 62% reductions and females 54% and 42% reductions respectively. The differences in relative age related decline would suggest that males experience a greater age-related decrement compared with
women. In order to identify any difference in the acute adaptability of tendon properties between genders, mechanical properties of the medial gastrocnemius tendon were assessed pre and post completion of a 5 minute passive dorsiflexion stretch in a young population group.
Females showed a significantly greater decrease in stiffness and Young's Modulus following stretch compared to males (Females: -22.4 % and -20.5 % vs. Males: -8.8 % and -8.4 %, p<0.05).
Finally, a study was completed investigating female's tendon mechanical properties over the course of the menstrual cycle, in relation to the fluctuating levels of serum oestrogen and progesterone. Analysis revealed no significant change in the structural and mechanical
properties of the medial gastrocnemius tendon between days 1-4, 12-14 and 20-23 of the menstrual cycle (p>0.05).